In order to realize safe travel of a vehicle, research and development is underway regarding devices that detect dangerous phenomena around a vehicle and automatically control the steering, accelerator, and brakes of the vehicle to avoid any dangerous phenomena that has been detected, and such devices have already been installed in some vehicles. Among such devices, a system that senses a pedestrian crossing in front of the vehicle with a sensor installed in the vehicle and warns the driver or automatically applies the brakes if there is a possibility of colliding with the pedestrian is effective in terms of enhancing the vehicle safety.
A camera or radar and a processing device that processes signals therefrom are used to sense a pedestrian in front of the vehicle with a sensor installed in the vehicle. In order to improve the sensing performance thereof, it is necessary to execute more detailed processes in the processing device. However, the computation resources of such a processing device are limited, and the processing device must simultaneously process other objects to be sensed in addition to the process for sensing a pedestrian. Thus, it is necessary to assign a priority to the processes and intensively execute the calculation processes. In order to achieve this, PTL 1 discloses one effective means for intensively executing processes in a scene in which there is a high possibility that a pedestrian exists, and PTL 1 further discloses an existence probability indicating the possibility that a pedestrian exists.